It's supposed to be incredibly hot here today and tomorrow, as the heat wave that's gripped part of the U.S. this week makes its way east. Not that it's been cool or anything, but they say the temps will hit the high 90s, and the heat index will be in the 120s(!). Is it too early for a cold beer?

Heat index involves humidity. Humidity affects your bodies ability to cool itself, so a 120 on the heat index means that, while it may only be in the high 90s, it's the equivalent of 120 in a dry climate.